1. Field of the Invention
This invention relates to novel cephem derivatives useful as antibacterial agents, process for the production thereof, antibacterial composition, intermediates thereof and process therefor.
2. Description of the Prior Art
A number of compounds have heretofore been known which contain a substituted thiadiazolylacetamido group or substituted thiazolylacetamido group at the 7-position of the cephem skeleton. For example, the compounds may be disclosed in the following publications: Japanese Patent Application Laid-open Nos. 11600/1980, 105689/1980, 24389/1982, 81493/1982, 4789/1983, 41887/1983, 59992/1983, 149296/1981, 102293/1977, 116492/1977, 125190/1977, 154786/1979, 192394/1982, 219292/1984, 97982/1985, 197693/1985, 231683/85, etc.
Particularly, 7.beta.-[(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3-(1-quinucl idinio)methyl-3-cephem-4-carboxylate is described in Japanese Patent Application Laid-open Nos. 219292/1984, 197693/1985, and 231683/1985. However, this compound can not be practically used from a clinical point of view, because its acute toxic value [LD.sub.50 (mouse, intravenous injection)] amounts to about 100 mg/kg or less, and hence, the compound is very toxic.